A leaky feeder system is a communication system used in facilities, on structures and in areas where 2-way communications signal coverage is poor. Typical applications include buildings, airplanes, mines and tunnels. A leaky feeder communication system consists of a head end base unit, coaxial cable, signal amplifiers and amplifier power supplies. The cable is routed throughout the area that needs signal coverage and “leaks” radio signal through gaps between the electrical shield(s). As the signal leaks, losing strength, the signal amplifiers, installed in line approximately every 1000-3000 feet, boost the signal for coverage down the next length of cable. Using this cascading technique, leaky feeder systems provide 2-way communications for miles. Users carry 2-way radios that transmit and receive through the leaky feeder system throughout the system as well as back to the head end unit for surface and remote locations.
During an emergency situation leaky feeder communications may be the only means of providing effective communications. The United States 2006 MINER Act amends the Federal Mine safety and Health Act of 2006 stating that underground mine operators must provide for post accident communication between underground and surface personnel via a wireless two-way medium within three years. This act required mines to install hundreds of leaky feeder communications systems throughout the United States and maintain these systems as mines continue to grow in length.
The leaky feeder base stations are connected to an Operations Center above ground. In the event of a disaster, leaky feeder systems are required to stay in operation, providing a means to communicate with personnel still underground. The personnel may be able to communicate, but there are virtually no lights in underground mines. The only lights available are personal head-lamps that use a re-chargeable battery sufficient for only 8-12 hours. There are no backup supplies of headlamps or underground charging stations. During an emergency event all power is disconnected to the mines to prevent an electrical ignition of methane so no alternative power is available. The leaky feeder system is required to stay energized to provide communications during the emergency event and is intrinsically safe meaning that the system is designed to prevent electrical ignitions of methane. With no power underground and head lamps having a limited charge the inevitable problem is total darkness for those still in the mine.
What is needed to overcome the problems associated in prior art of headlamps is the continuous availability of light for escape way marking, location indication and area lighting in facilities, structures and critically in mines and tunnels.